This project describes patterns and correlates of use of specialized therapies (physical therapy, occupational therapy, speech therapy, language therapy, respiratory therapy, and home health) in children and in children with chronic conditions and injuries. The project has three objectives: 1) to describe patterns of use and expenditures for specialized therapies for children with and without chronic conditions, 2) to determine correlates of specialized therapy use among children including predisposing, enabling, and need characteristics, and, 3) to understand how use of providers affects use. The project will use data from four data sources, the National Health Interview Survey on Disability, the Medical Expenditure Panel Survey, the 5 percent sample of Medi-Cal eligibility and encounter data, California's fee-for-service Medicaid plan, and a cohort of children in Harvard Vanguard Health Associates. Descriptive analyses will include examining patterns of use among chronically and non-chronically ill children and understanding absolute and relative expenditures of therapies. The study will further examine the role of primary and specialty providers as predictors of specialized therapy use. This project will provide the first comprehensive and systematic description of the use, expenditures, and predictors of specialized therapies by children. Understanding the correlates of use and expenditures will provide information about children who have relatively rich versus relatively sparse use of services. This information will help health plans to better predict future use. It will help advocates who may seek to change policies that influence access for subpopulations. This study will provide useful information in discussions regarding care co-ordination and interagency systems.